gcc --version varies too much for sane comparisons with vmlinux's
.comment section. Therefore compile a test file and compare its .comment
section.
Also fix gcc 4.8 check which used a lexicographically comparison which
will break for gcc versions >= 10. Instead check for the required
compiler options.
Closes#565.
- Replace grep | wc -l with grep -c.
- Use find -print0 and xargs -0 to handle non-alphanumeric filenames
(shouldn't be an issue for us but it's good practice).
- Replace expr with $(( )).
Found by shellcheck.
The double quotes are confusing as they don't quote $UBUNTU_ABI and thus
have no real effect. As $UBUNTU_ABI is a number simply remove them and
put $UBUNTU_ABI into the surrounding quotes.
Found by shellcheck.
- Replace echo $(cmd) with just cmd.
- Replace $@ inside quotes with $*.
- Always die if cd fails.
- Ensure rm -rf "$TEMPDIR"/* never expands to rm -rf /*.
Found by shellcheck.
Without proper quoting kpatch fails if the argument contains spaces, the
other scripts might be affected as well.
Not all new quotes are strictly necessary but they were added for
consistency with the existing code and to prevent copy & paste errors in
the future.
There's one conversion which is not straight-forward:
- grepname=$grepname\\\.o
+ grepname="$grepname\.o"
There are different quoting rules with and without the double quotes.
Valgrind complains about an uninitialized variable in
create-klp-module.c:
==4412== Conditional jump or move depends on uninitialised value(s)
==4412== at 0x402846: main (create-klp-module.c:497)
This warning refers to main()'s struct arguments stack variable,
precisely its .no_klp_arch member. Initialize the entire structure to
zero to avoid complaint.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Valgrind complains about uninitialized bytes passed to pwrite64(buf)
from kpatch_write_output_elf()'s call to elf_update():
==32378== Syscall param pwrite64(buf) points to uninitialised byte(s)
==32378== at 0x5141A03: __pwrite_nocancel (in /usr/lib64/libc-2.23.so)
==32378== by 0x4E46846: ??? (in /usr/lib64/libelf-0.168.so)
==32378== by 0x4E42B88: elf_update (in /usr/lib64/libelf-0.168.so)
==32378== by 0x40C57A: kpatch_write_output_elf (kpatch-elf.c:895)
==32378== by 0x40926F: main (create-diff-object.c:2851)
==32378== Address 0x28d52300 is 0 bytes inside a block of size 56 alloc'd
==32378== at 0x4C2BBAD: malloc (vg_replace_malloc.c:299)
==32378== by 0x40B86A: create_section_pair (kpatch-elf.c:707)
==32378== by 0x406CAE: kpatch_create_patches_sections (create-diff-object.c:2109)
==32378== by 0x4090C5: main (create-diff-object.c:2815)
These are fields which we don't need to populate (like a
funcs[index].new_addr value that will be filled by relocation). The
easiest way to appease valgrind and not clutter the code is to just
zero-out this entire buffer on allocation.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Now that kpatch-build can accept multiple patches on the command line,
ditch the combinediff and associated logic in the integration test
script.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
I couldn't find a good place in the document for this, so I just added
an "Other issues" section at the end.
Fixes#738.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
kpatch-elf.c is used by binaries other than create-diff-object, but
create-diff-object is the only one that cares about "bundling". Move
the bundling to create-diff-object.
Fixes#700.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
The create_klp_relasecs_and_syms() function assumes that all dest
symbols are bundled, i.e. each symbol is located at offset 0 in its own
section.
However that may not always be the case. Unbundled symbols can occur,
for example, when combining two .o files which have the same bundled
symbol. They will be combined into the same section and will no longer
be considered "bundled".
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
The create_dynamic_rela_sections() function assumes that all dest
symbols are bundled, i.e. each symbol is located at offset 0 in its own
section.
However that may not always be the case. Unbundled symbols can occur,
for example, when combining two .o files which have the same bundled
symbol. They will be combined into the same section and will no longer
be considered "bundled".
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Use kpatch-<modname>.ko or livepatch-<modname>.ko depending on the type
of module we're building.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
It can be convenient to build a patchset into a single kpatch module, so
teach kpatch-build to accept a list of .patch files on the commandline.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Add commandline option to specify the kpatch module name, else derive it
from the .patch filename.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
When there is a ".." in the source object path, kpatch-gcc can't handle
it correctly. kpatch-gcc is called for objects which were recompiled
and writes the changed objects to "changed_objs". But if the path of the
input obj is something like:
arch/x86/kvm/../../../virt/kvm/.tmp_kvm_main.o
then it will fall into the "*.*.o" branch of the kpatch-gcc case
statement and kpatch-build will report "ERROR: no changed objects
found."
Use Joe's suggestion to revert d526805619 ("kpatch-gcc: update
ignorelist to avoid foo/.lib_exports.o files") and instead add a
"*/.lib_exports.o" pattern.
Fixes#735.
[ cleaned up changelog - jpoimboe@redhat.com ]
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: chen xiaoguang <xiaoggchen@tencent.com>
Normally, kpatch doesn't complain if you remove or rename a function.
This is a feature, because sometimes you have to rename a function in
order to patch it, if for example it doesn't have an fentry call. In
the object code, it's treated as a new function. You could get the same
result by copying/pasting the original function and giving the copy a
new name. But renaming it makes it much easier to review the patch.
In RHEL 7.4, I tried to rename l2cap_config_rsp() to
l2cap_config_rsp_kpatch(), but it failed with:
ERROR: l2cap_core.o: reference to static local variable CSWTCH.347 in l2cap_config_rsp was removed
This particular error is an easy fix, because the CSWTCH.* symbols are
read-only and are created by GCC. So they shouldn't be correlated
anyway.
In the future, we will need a more general fix to allow the removal of
functions which use *any* static local variables. Either automatically,
or by adding a manual annotation. This can be handled when we rewrite
the static local variable handling in #545.
Instead of always using the maximum number of CPUs available, allow
user to tune the number of make jobs using the command line argument
('-j', '--jobs').
If an .LCx symbol gets renamed or changes sections, or if its section
gets renamed, kpatch-build will get confused.
They aren't *real* symbols, just string constants. So no need to
correlate and compare them.
Fixes#714.
Fixes#727.
This removes duplicate code which is already handled by make internally
and also respects CPPFLAGS.
LDFLAGS are general linker flags, LDLIBS should be used for the
libraries itself. Therefore switch to LDLIBS which is put after the
object files in the command line (which is not true for LDFLAGS).
With gcc-6 the function prologue is changeg by
moving the toc base resolution func - 0x8 bytes:
.globl my_func
.type my_func, @function
.quad .TOC.-my_func
my_func:
.reloc ., R_PPC64_ENTRY ; optional
ld r2,-8(r12)
add r2,r2,r12
.localentry my_func, .-my_func
Add support for function prologue, along with gcc-5.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Add support for ppc64le specific special sections:
- __ftr_fixup
- __mmu_ftr_fixup
- __fw_ftr_fixup
- __lwsync_fixup
This patch also add #ifdef guards for architecture specific
special sections.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
This patch adds support for livepatch hook based module
creation for PPC64le. It introduces PPC64le architecture
bits:
- Add relocation type of R_PPC64_ADDR64 while parsing powerpc ELF.
- Introduce .toc sections mainpulation.
- Skip kpatch specific details for livepatch hook.
Also remove the definition of rela_insn() for powerpc. The only
call site is been guarded by #ifdef x86.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
symbol->has_fentry_call is x86 specfic. Rename it to more
generic name, representing the general idea of calling
profiling function at function entry.
This patch converts all instance of symbol->has_fentry_call
to symbol->has_func_profiling and also renames functions:
kpatch_check_fentry_calls() -> kpatch_check_func_profiling_calls()
kpatch_find_fentry_calls() -> kpatch_find_func_profiling_calls()
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Move special section data checks to helper function
find_special_section_data(). Special section data will differ
between architectures and all architecture specific and common
checks can be handled better within a helper function.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
gcc -mprofile-kernel support is required on ppc64le for livepatch
to work. Check should be performed on the gcc, instead of relying
on the verion number.
This check is already performed during the kernel build by:
<linux-sources>/arch/poweprc/tools/gcc-check-mprofile-kernel.sh
Bail out, during the kernel build. Incase the gcc lacks the support
for -mprofile-kernel, instead of duplicating the check in kpatch-buid.
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
